1. Field of the Invention
The invention relates to an imaging device suitable for nighttime imaging and the like, as well as a visual recognition support system employing device thereof.
2. Description of the Related Art
JPA 5-56341 discloses an example of a known imaging device which uses a CCD to photoelectric-convert and output light coming in through an imaging optical system. This imaging device controls the amount of light transmitted to the image optical system and the light storage time of an image pickup device, as well as variably controls the gain of the image pickup device output. In a predetermined imaging mode, the imaging device increases the gain to shorten the setting of the light storage time in an attempt to realize optimal exposure control regardless of the imaging situation.
However, with this imaging device problems, such as halation being generated in the image display, may arise depending on the conditions in which the image is captured (i.e., the imaging conditions). For example, when the imaging device is used in a visual recognition support system which provides a driver with visual recognition support when driving a vehicle at night, the image output is set high in order to enable the driver to recognize pedestrians and the like on the road in front of the vehicle when it is dark. However, when the image output is set in this way and the imaging device picks up headlights from an oncoming vehicle, for example, there is a large halation effect such that suitable imaging can not be obtained.